The invention generally relates to systems and methods for cosmetic tissue treatments and, more particularly, relates to systems and methods for treating tissue with high frequency electromagnetic energy.
Various cosmetic tissue procedures non-invasively treat tissue with high frequency electromagnetic energy in order to improve a patient's appearance. These non-invasive, procedures involve no surgery or injections, but instead deliver the high frequency electromagnetic energy through the skin surface into the tissue. High frequency electromagnetic energy applied to the different layers of the skin during a cosmetic tissue procedure can have a physiological effect on the skin's appearance.
The high frequency electromagnetic energy may be delivered from a conductor region of a treatment electrode to the tissue. The conductor region of the treatment electrode may be in contact with the tissue surface. Generally, a higher energy density of high frequency electromagnetic energy is delivered at the perimeter of the treatment electrode as an artifact of the edge at the perimeter. This edge effect produces observable results.
The transferred electromagnetic energy heats the tissue. One result of the edge effect is that the tissue heating is non-uniform across the surface area of the conductor region. Specifically, tissue proximate to the outer peripheral edge of the treatment electrode is heated to a higher temperature compared with tissue inward from the outer peripheral edge. Another result of the edge effect is that the patient may experience heat-related pain. This heat-related pain may be alleviated by reducing the treatment level. However, the reduction in treatment level to alleviate pain reduces the average energy density delivered during the treatment procedure, which lessens the effectiveness of the treatment.
What is needed, therefore, are apparatus and methods for reducing the edge effect associated with such tissue treatments so that patient discomfort is alleviated, a higher average energy density can be delivered, and therapeutic results can be improved.